The present invention relates to apparatus for securing belt fasteners to a belt end. More particularly, the apparatus is a fastener for fastening stirrup-like or loop-type fasteners to a conveyor belt end. The secured fasteners have an extending loop and aperture for mating with an opposed belt-end arrangement of fasteners, which meshed fasteners cooperate and have a hinge loop for insertion of a rod for the coupling of the belt ends to provide a continuous belt.
The present invention is directed to an apparatus for driving staples through a belt to connect belt fasteners to a belt end. Tools to drive and clinch the staples to attach the belt fasteners to a belt end, often are operated in very difficult environments, such as in coal mines, where moisture and rock dust abound. In many mines, such as coal mines, pulverized limestone is used to coat the walls or ceilings to keep down the amount of coal dust in the air and thereby prevent explosions. Such pulverized rock material is everywhere and has a tendency to infiltrate operating parts of equipment and to act as a pumice to grind on rotating or mating sliding parts. Also, such rock dust and coal dust may accumulate inside of the staple applying tool and cause malfunctions particularly when the tool has several springs, levers and small operating parts.
In addition to operating in adverse conditions, it is preferred that the staple applying and clinching tool operate manually with an acceptable level of force. The particular location for attachment of belt fasteners to make a splice may be one where hydraulic or pneumatic drives for the tool are not available and the belt fasteners must be attached to the belt end by mechanical force applied by a person. Manifestly, the person providing the force for driving a plurality of staples for each belt fastener across a wide belt end prefers a tool that is less exhausting to work over a tool that requires greater force. The amount of force needed to bend and clinch the staples has increased with the switch from the more ductile steel staples to the less ductile stainless steel staples. The staple ends are bent over at 90.degree. at their free ends; and such bending of stainless steel staple-free ends requires a considerable degree of force which, in the preferred embodiment, is generated by the operator using a mechanical machine. With more and heavier and diverse interior plies and cords in the belts, the job of driving the staple ends through the belt carcass has become increasingly difficult.
In addition to bending the staple-free ends over at 90.degree. to clinch the belt fasteners to the belt end, the tool should force the belt fastener legs or plates on opposite sides of the belt tight against the upper and lower faces of the belt. That is, at the time of clinching the belt fastener, legs or plates should be pushed tightly against the belt so that they are not loose after the staples have been clinched.
Other considerations in a practical and commercially-acceptable tool for applying such forces and for operating in such adverse conditions, are to keep the tool cost competitive with other tools and to make it relatively maintenance-free and to have a relatively long life such that the tool does not wear out quickly. Also, the tool should be fairly simple to operate and should be relatively foolproof in its operation. Additionally, the belt fasteners must be spaced evenly to accept the hinge loop or knuckle from the belt fasteners on the other belt end for the splice. The tool operations for indexing and for registering the staple applying and bending mechanism at locations along the belt end should be mutually exclusive and noninterfering with the belt penetration and the staple-clinching actions.
Tools for applying and securing these various fasteners to belt ends include hand-driven punch and anvil apparatus; pneumatic and hydraulic tools; and, manually-operated fastening apparatus. The swinging of hammers or mauls to drive staples through belts and then to clinch may result in injury to the worker and is certainly fatiguing relative to the lever-operated devices now in use. An old hand-driven punch and anvil arrangement is disclosed and illustrated in Hobson U.S. Pat. No. 3,261,085, which has an upper plate with a comb to retain a plurality of staples to be driven into plate-like fasteners, and a chisel-like tool to drive a plurality, such as three, of staples with a single blow from a hammer. The driven staple ends extend through a belt and fastener to contact an arcuate anvil or lower surface to partially deform their end points. Thereafter, the fastening machine is indexed to position the formed staple ends above a flat surface for a second blow to final-clinch the staples and fastener to the belt end. An alternative apparatus also has an upper comb to retain a plurality of staples for insertion into U-shaped fasteners. The staples are manually driven through the fasteners and partially formed on a lower anvil surface. Subsequently, the upper comb is raised, a flat plate is overlaid the lower anvil surface, the belt end is repositioned over this flat, plate-like surface, for delivery of a second and final-clinching blow to the formed staples and fasteners on the belt end. A lever-operated guide comb and an anvil to flatten the staple points after their insertion into the fasteners is shown in French Patent No. 2,582,369.
Other fastener apparatus are provided which utilize a movable die arrangement on a bed assembly for sequential fastener forming, staple driving and final clinching of staples in stirrup-like fasteners. These fastening apparatus are frequently operable by handles coupled to tools through mechanical linkage, which drives a punch through a comb bed, thrusting a staple through a fastener end, and securing the staple by a final clinching action. The tool or die head is indexed to finally clinch and sequentially perform these functions on successive fasteners and staples. This operation is particularly illustrated in U.S. Pat. No. 4,789,092, which has a die operator movable by an indexing handle along a comb-bed assembly.
Belt-fastening staples may be inserted by a tool through fastener ends and may merely be deformed by pressing against a flat plate lower surface or an angled, anvil-type surface. A tool to perform this operation is provided in U.S. Pat. No. 3,458,099, where the staples are driven through the belt end and the staple ends are formed on a lower plate or anvil surface in opposed directions along the fastener end. Similarly, British Patent No. 1,566,409 illustrates a flat lower plate surface for forming the staple points after insertion in the belt and fastener end.
Other staple-securing apparatus are available which utilize a wiping action to form the staple ends after insertion for clinching the staples in fasteners for conveyor belts. The staples are driven through the fasteners and belt and, thereafter, by moving either the formed fastener and belt or the lower angled tool surface, the staple ends are bent to the form of the lower or upper surface of the fastened joint. The force required to wipe the staple ends, particularly when made of stainless steel, is quite large. The other difficulty with such wiping tools is how to force the belt fastener plates tightly against the belt while wiping across in a direction 90.degree. to the direction of force application to push the belt fastener legs or plates into the belt faces. Representative of these wiping-action tools are Stolz U.S. Pat. No(s). 4,522,329 and 4,050,138; Neale U.S. Pat. No(s). 3,142,842 and 3,101,481; and British Patent 1,325,063--Hobson.
The above-noted assemblies do not provide a sequential drive apparatus for securing staples and fasteners along a belt end, which apparatus has a positive locating means, that insures proper tool alignment prior to tool insertion and retains the tool drive apparatus at its location until the tools are withdrawn to a reference position.